CONVERT YOUR 2001-2005 ALLISON 5 SPEED TO 6 SPEEDS Drops 325 engine rpm @ 75 mph with 3.73 gears. Increases fuel economy 1 - 1.5 MPG, reduces engine noise while cruising, a truck with 3.73 gears that normally likes cruising at 62 MPH will now cruise nice at 72 MPH. The gear ratio in your 5 speed is .71 and our 6th gear will be .61. 6th gear can be disabled with your two haul button and 5th canceled with OD off. Requires valve body and tcm change (1 hour). No wiring, no modifications required. Indicate LB7 or LLY & year.
*Core deposit required.
Merchant Automotive, Your diesel performance destination. We Ship within the U.S. and Worldwide Daily. © 2011